Apparatus and Method for Modulating Data Message By Employing Orthogonal Variable Spreading Factor (OVSF) Codes in Mobile Communication System

ABSTRACT

A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses at least one channel, includes the steps of: a) encoding the source data to generate at least one data part and a control part; b) generating at least one spreading code to be allocated to the channel, wherein each spreading code is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on same point or symmetrical with respect to a zero point on a phase domain; and c) spreading the control part and the data part by using the spreading code, to thereby generate the channel-modulated signal. The method is capable of improving a power efficiency of a mobile station by reducing a peak-to-average power ratio in a mobile communication system.

FIELD OF THE INVENTION

The present invention relates to an apparatus and method for modulatinga data message in a mobile communication system; and, more particularly,to an apparatus and method for modulating a data message by employingorthogonal variable spreading factor (OVSF) codes in a mobilecommunication system.

DESCRIPTION OF THE PRIOR ART

Generally, a mobile communication system such as an international mobiletelecommunication-2000 (IMT-2000) system is capable of providing variousservices of good quality and large capacity, an international roamingand so on. The mobile communication system can be applicable tohigh-speed data and multimedia services such as an Internet service andan electronic commerce service. The mobile communication system carriesout orthogonal spread with respect to multiple channels. The mobilecommunication system allocates the orthogonal spread channels to anin-phase (I) branch and a quadrature-phase (Q) branch. A peak-to-averagepower ratio (PAPR) needed to simultaneously transmit I-branch data andQ-branch data affects power efficiency of a mobile station and a batteryusage time of the mobile station.

The power efficiency and the battery usage time of the mobile stationare closely related to a modulation scheme of the mobile station. As amodulation standard of IS-2000 and asynchronous wideband-CDMA, themodulation scheme of orthogonal complex quadrature phase shift keying(OCQPSK) has been adopted. The modulation scheme of OCQPSK is disclosedin an article by JaeRyong Shim and SeungChan Bang: ‘Spectrally EfficientModulation and Spreading Scheme for CDMA Systems’ in electronicsletters, Nov. 12, 1998, vol. 34, No. 23, pp. 2210-2211.

As disclosed in the article, the mobile station carries out theorthogonal spread by employing a Hadamard sequence as a Walsh code inthe modulation scheme of the OCQPSK. After the orthogonal spread, I andQ channels are spread by a Walsh rotator and a spreading code, e.g., apseudo noise (PN) code, a Kasami code, a Gold code and so on.

Further, as for multiple channels, the mobile station carries out theorthogonal spread by employing different Hardamard sequences. After theorthogonal spread, the orthogonal spread channels are coupled to I and Qbranches. Then, the orthogonal spread channels coupled to the I branchand the orthogonal spread channels coupled to the Q branch is separatelysummed. The I and Q branches are scrambled by the Walsh rotator and thescrambling code. However, there is a problem that the above-mentionedmodulation scheme can not effectively reduce the PAPR in the mobilecommunication system.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide anapparatus and method for modulating a data message that is capable ofimproving a power efficiency of a mobile station by reducing apeak-to-average power ratio in a mobile communication system.

In accordance with an embodiment of an aspect of the present invention,there is provided an apparatus for converting source data to achannel-modulated signal having a plurality of pairs of in-phase (I) andquadrature-phase (Q) data in a mobile station, wherein the mobilestation uses at least one channel, comprising: channel coding means forencoding the source data to generate at least one data part and acontrol part; code generating means for generating at least onespreading code to be allocated to the channel, wherein each spreadingcode is selected on the basis of a data rate of the data part and thecontrol part and spreading codes are selected so that two consecutivepairs of the I and Q data are correspondent to two points located onsame point or symmetrical with respect to a zero point on a phasedomain; and spreading means for spreading the control part and the datapart by using the spreading code, to thereby generate thechannel-modulated signal.

In accordance with another embodiment of the aspect of the presentinvention, there is provided an apparatus for converting source data toa channel-modulated signal having a plurality of pairs of in-phase (I)and quadrature-phase (Q) data in a mobile station, wherein the mobilestation uses N number of channels where N is a positive integer,comprising: channel coding means for encoding the source data togenerate (N−1) number of data parts and a control part; code generatingmeans for generating N number of spreading codes to be allocated to thechannels, wherein each spreading code is selected on the basis of a datarate of each data part and the control part and the spreading codes areselected so that two consecutive pairs of the I and Q data arecorrespondent to two points located on same point or symmetrical withrespect to a zero point on a phase domain; and spreading means forspreading the control part and the data parts by using the spreadingcodes, to thereby generate the channel-modulated signal.

In accordance with an embodiment of another aspect of the presentinvention, there is provided a mobile station for converting source datato a channel-modulated signal having a plurality of pairs of in-phase(I) and quadrature-phase (Q) data, wherein the mobile station uses Nnumber of channels where N is a positive integer, comprising: channelcoding means for encoding the source data to generate (N−1) number ofdata parts and a control part; code generating means for generating Nnumber of spreading codes to be allocated to the first and the secondchannels, wherein each spreading code is selected on the basis of a datarate of each data part and the control part and the spreading codes areselected so that two consecutive pairs of the I and Q data arecorrespondent to two points located on same point or symmetrical withrespect to a zero point on a phase domain; and spreading means forspreading the control part and the data parts by using the spreadingcodes, to thereby generate the channel-modulated signal.

In accordance with an embodiment of further another aspect of thepresent invention, there is provided a method for converting source datato a channel-modulated signal having a plurality of pairs of in-phase(I) and quadrature-phase (Q) data in a mobile station, wherein themobile station uses at least one channel, comprising the steps of: a)encoding the source data to generate at least one data part and acontrol part; b) generating at least one spreading code to be allocatedto the channel, wherein each spreading code is selected on the basis ofa data rate of the data part and the control part and spreading codesare selected so that two consecutive pairs of the I and Q data arecorrespondent to two points located on same point or symmetrical withrespect to a zero point on a phase domain; and c) spreading the controlpart and the data part by using the spreading code, to thereby generatethe channel-modulated signal.

In accordance with another embodiment of further another aspect of thepresent invention, there is provided a method for converting source datato a channel-modulated signal having a plurality of pairs of in-phase(I) and quadrature-phase (Q) data in a mobile station, wherein themobile station uses N number of channels where N is a positive integer,comprising: a) encoding the source data to generate (N−1) number of dataparts and a control part; b) generating N number of spreading codes tobe allocated to the channels, wherein each spreading code is selected onthe basis of a data rate of each data part and the control part and thespreading codes are selected so that two consecutive pairs of the I andQ data are correspondent to two points located on same point orsymmetrical with respect to a zero point on a phase domain; and c)spreading the control part and the data parts by using the spreadingcodes, to thereby generate the channel-modulated signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and features of the instant invention willbecome apparent from the following description of preferred embodimentstaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram illustrating a mobile station to which thepresent invention is applied;

FIG. 2 is an exemplary view illustrating a tree structure of spreadingcodes applied to the present invention;

FIG. 3 is an exemplary block diagram depicting a modulator shown in FIG.1 in accordance with the present invention;

FIG. 4 is a block diagram describing a spreading code generator shown inFIG. 3;

FIG. 5 is an exemplary diagram illustrating a case where a mobilestation uses two channels;

FIG. 6 is an exemplary diagram depicting a case where multiple mobilestations share a common complex-valued scrambling code;

FIG. 7 is an exemplary diagram showing a case where a mobile stationuses multiple channels;

FIG. 8 is a first exemplary view describing a desirable phase differencebetween rotated points on a phase domain where a Walsh rotator rotatespoints at consecutive chips;

FIG. 9 is a second exemplary view showing a desirable phase differencebetween rotated points on a phase domain where a Walsh rotator rotatespoints at consecutive chips;

FIG. 10 is a first exemplary view depicting an undesirable phasedifference between rotated points on a phase domain where a Walshrotator rotates points at consecutive chips;

FIGS. 11 and 12 are third exemplary views illustrating a desirable phasedifference between rotated points on a phase domain where a Walshrotator rotates points at consecutive chips;

FIGS. 13 and 14 are second exemplary views illustrating an undesirablephase difference between rotated points on a phase domain where a Walshrotator rotates points at consecutive chips;

FIG. 15 is a graphical diagram describing the probability of peak powerto average power; and

FIGS. 16 to 22 are flowcharts illustrating a method for modulating adata message in a mobile station in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, there is shown a block diagram illustrating amobile station to which the present invention is applied. As shown, themobile station includes a user interface 20, a central processing unit(CPU) 180, a modem 12, a source codec 30, a frequency converter 80, auser identification module 50 and an antenna 70. The modem 12 includes achannel codec 13, a modulator 100 and a demodulator 120. The channelcodec 13 includes an encoder 110 and a decoder 127.

The user interface 20 includes a display, a keypad and so on. The userinterface 20, coupled to the CPU 180, generates a data message inresponse to a user input from a user. The user interface 20 sends thedata message to the CPU 180.

The user identification module 50, coupled to the CPU 180, sends useridentification information as a data message to the CPU 180. The sourcecodec 30, coupled to the CPU 180 and the modem 12, encodes source data,e.g., video, voice and so on, to generate the encoded source data as adata message. Then, the source codec 30 sends the encoded source data asthe data message to the CPU 180 or the modem 12. Further, the sourcecodec 30 decodes the data message from the CPU 180 or the modem 12 togenerate the source data, e.g., video, voice and so on. Then, the sourcecodec 30 sends the source data to the CPU 180.

The encoder 110, contained in the channel codec 13, encodes the datamessage from the CPU 180 or the source codec 30 to generate one or moredata parts. Then, the encoder 110 generates a control part. The encoder110 sends the one or more data parts to the modulator 100. The modulator100 modulates the one or more data parts and the control part togenerate I and Q signals as baseband signals. The frequency converter 80converts the baseband signals to intermediate frequency (IF) signals inresponse to a conversion control signal from the CPU 180. Afterconverting the baseband signals to the IF signals, the frequencyconverter 80 converts the IF signals to radio frequency (RF) signals.The frequency converter 80 sends the RF signals to the antenna 70.Further, the frequency converter 80 controls a gain of the RF signals.The antenna 70 sends the RF signals to a base station (not shown).

The antenna 70 sends the RF signals from the base station to thefrequency converter 80. The frequency converter 80 converts the RFsignals to the IF signals. After converting the RF signals to the IFsignals, the frequency converter 80 converts the IF signals to thebaseband signals as the I and Q signals. The demodulator 90 demodulatesthe I and Q signals to generate the one or more data parts and thecontrol part. The decoder 127, contained in the channel codec 13,decodes the one or more data parts and the control part to generate thedata message. The decoder 127 sends the data message to the CPU 180 orthe source codec 30.

Referring to FIG. 2, there is shown an exemplary view illustrating atree structure of spreading codes as orthogonal variable spreadingfactor (OVSF) codes applied to the present invention. As shown, aspreading code is determined by a spreading factor (SF) and a codenumber in a code tree, wherein the spreading code is represented byC_(SF, code number). C_(SF, code number) is made up of a real-valuedsequence. The SF is 2^(N) where N is 0 to 8, and the code number is 0 to2^(N)−1. $\begin{matrix}\begin{matrix}{\begin{bmatrix}C_{2,0} \\C_{2,1}\end{bmatrix} = \begin{bmatrix}C_{1,0} & C_{1,0} \\C_{1,0} & {- C_{1,0}}\end{bmatrix}} \\{= \begin{bmatrix}1 & 1 \\1 & {- 1}\end{bmatrix}} \\{{{where}\quad C_{1,0}} = 1}\end{matrix} & {{Eq}.\quad(1)} \\{\begin{bmatrix}C_{2^{({N + 1})},0} \\C_{2^{({N + 1})},1} \\C_{2^{({N + 1})},2} \\C_{2^{({N + 1})},3} \\\vdots \\C_{2^{({N + 1})},{2^{({N + 1})} - 2}} \\C_{2^{({N + 1})},{2^{({N + 1})} - 1}}\end{bmatrix} = {\begin{bmatrix}C_{2^{N},0} & C_{2^{N},0} \\C_{2^{N},0} & {- C_{2^{N},0}} \\C_{2^{N},1} & C_{2^{N},1} \\C_{2^{N},1} & {- C_{2^{N},1}} \\\vdots & \vdots \\C_{2^{N},{2^{N} - 1}} & C_{2^{N},{2^{N} - 1}} \\C_{2^{N},{2^{N} - 1}} & {- C_{2^{N},{2^{N} - 1}}}\end{bmatrix}\quad{where}\quad N\quad{is}\quad 1\quad{to}\quad 7}} & {{Eq}.\quad(2)}\end{matrix}$

For example, a spreading code having an SF of 8 and a code number of 1is represented by C_(8, 1)={1, 1, 1, 1, −1, −1, −1, −1} according toEqs. (1) and (2). In case where the SF is more than 2, the spreadingcodes are grouped by two groups, including a first group and a secondgroup according to a code number sequence. The first group includes thespreading codes with the SF and code numbers of 0 to SF/2−1 and thesecond group includes the spreading codes with the SF and code numbersof SF/2 to SF−1. Therefore, the number of spreading codes contained inthe first group is the same as that of spreading codes contained in thesecond group.

Each spreading code contained in the first or second group is made up ofreal values. Each spreading code contained in the first or second groupcan be employed in an OCQPSK modulation scheme. It is preferred that aspreading code, contained in the first group, is selected for the OCQPSKmodulation scheme. However, where a spreading code, contained in thesecond group, is multiplied by another spreading code with a minimumcode number, i.e., SF/2, contained in the second group, themultiplication of the spreading codes, contained in the second group,becomes the same as a spreading code contained in the first group.Accordingly, the multiplication of the spreading codes contained in thesecond group is represented by a spreading code of the first group. As aresult, all the spreading codes, i.e., OVSF codes, of the first andsecond groups are useful for reducing the peak-to-average power ratio(PAPR) of the mobile station.

Referring to FIG. 3, there is shown a block diagram depicting amodulator shown in FIG. 1 in accordance with the present invention. Themobile communication system includes a base station and a mobile stationemploying a plurality of channels, wherein the mobile station includesthe modulator. The channels include a control channel and one or moredata channels.

The one or more data channels include a physical random access channel(PRACH), a physical common packet channel (PCPCH) and dedicated physicalchannel (DPCH). In a PRACH or PCPCH application, a control channel andonly one data channel, i.e., PRACH or PCPCH, are coupled between theencoder 110 and the spreader 130. The DPCH includes dedicated physicaldata channels (DPDCHs). In a DPCH application, a dedicated physicalcontrol channel (DPCCH) as a control channel and up to six datachannels, i.e., DPDCH 1 to DPDCH 5 are coupled between the encoder 110and the spreader 130. As shown, a modulator 100 includes an encoder 110,a code generator 120, a spreader 130, a scrambler 140, a filter 150, again adjuster 160 and an adder 170.

The encoder 110 encodes the data message to be transmitted to the basestation to generate one or more data parts. The encoder 110 generates acontrol part having a control information. The encoder 110 evaluates anSF based on a data rate of the one or more data parts.

The CPU 180, coupled to the encoder 110, receives the SF related to theone or more data parts from the encoder 110. The CPU 180 produces one ormore code numbers related to the one or more data parts and an SF and acode number related to the control part.

The code generator 120 includes a spreading code generator 121, asignature generator 122 and a scrambling code generator 123. The codegenerator 120, coupled to the CPU 180, generates spreading codes, i.e.,C_(d1) to C_(dn) and C_(c), a signature S and a complex-valuedscrambling code. The spreading code generator 121, coupled to the CPU180 and the spreader 130, generates the spreading codes in response tothe SF and the one or more code numbers related to the one or more dataparts and an SF and a code number related to the control part from theCPU 180. The spreading code generator 121 sends the spreading codes tothe spreader 130.

The signature generator 122, coupled to the CPU 180 and the spreadingcode generator 121, generates the signature S to send the signature S tothe spreading code generator 121. The scrambling code generator 123generates the complex-valued scrambling code to send the complex-valuedscrambling code to the scrambler 140.

The spreader 130 spreads the control part and the one or more data partsfrom the encoder 110 by the spreading codes from the code generator 120.

The scrambler 140 scrambles the complex-valued scrambling code, the oneor more data parts and the control part spread by the spreader 130,thereby generating scrambled signals. The scrambler 140 includes a Walshrotator, which is typically employed in the OCQPSK modulation scheme.The Walsh rotator rotates the one or more data parts and the controlpart spread by the spreader 130.

The filter 150, i.e., a root raised cosine (PRC) filter, pulse-shapesthe scrambled signals to generate pulse-shaped signals. The gainadjuster 160 multiplies each of the pulse-shaped signals by the gain ofeach channel, thereby generating gain-adjusted signals. The adder 170sums the gain-adjusted signals related to an I branch or thegain-adjusted signals related to a Q branch, to thereby generate achannel-modulated signal having a plurality of pairs of I and Q data inthe mobile station.

Referring to FIG. 4, there is shown a block diagram describing aspreading code generator shown in FIG. 3. As shown, the spreading codegenerator includes a storage device 210, an 8-bit counter 220, aplurality of logical operators 231 and 233 and a plurality ofmultiplexers 232 and 234.

The storage device 210 includes one or more registers 211 related to theone or more data parts and a register 212 related to the control part.The one or more registers 211 stores an SF and code numbers related tothe one or more data parts sent from the CPU 180 shown in FIG. 3. Theregister 212 stores an SF and a code number related to the control partsent from the CPU 180.

The 8-bit counter 220 consecutively produces a count value ofB₇B₆B₅B₄B₃B₂B₁B₀ as 8-bit count value in synchronization with a clocksignal CHIP_CLK issued from an external circuit, wherein B₀ to B₇ aremade up of a binary value of 0 or 1, respectively.

The one or more logical operators 231 carry out one or more logicaloperations with the SF and the code numbers related to the one or moredata parts stored in the one or more register 211, thereby generatingthe spreading codes related to the one or more data parts. A code numberis represented by I₇I₆I₅I₄I₃I₂I₁I₀, wherein I₀ to I₇ are the binaryvalue of 0 or 1, respectively.

The logical operator 233 carries out a logical operation with the SF andthe code number of I₇I₆I₅I₄I₃I₂I₁I₀ related to the control part storedin the register 212, thereby generating a spreading code related to thecontrol part. $\begin{matrix}{{\prod\limits_{i = 0}^{N - {2\quad \oplus `}}{{I_{i} \cdot B_{N - 1 - i}}\quad{where}\quad 2}} \leq N \leq 8} & {{Eq}.\quad(3)}\end{matrix}$

where “·” denotes a multiplication in modulo 2 and Π^(⊕) denotes anexclusive OR operation. Each logical operator 231 or 233 carries out alogical operation according to Eq. (3) where SF=2^(N).

If the SF is 256, each logical operator 231 or 233 carries out a logicaloperation of B₇·I₀⊕B₆·I₁⊕B₅·I₂⊕B₄·I₃⊕B₃·I₄⊕B₂·I₅⊕B₁·I₆⊕B₀·I₇

If the SF is 128, each logical operator 231 or 233 carries out a logicaloperation of B₆·I₀⊕B₅·I₁⊕B₄·I₂⊕B₃·I₃⊕B₂·I₄⊕B₁·I₅⊕B₀·I₆.

If the SF is 64, each logical operator 231 or 233 carries out a logicaloperation of B₅·I₀⊕B₄·I₁⊕B₃·I₂⊕B₂·I₃⊕B₁·I₄⊕B₀·I₅.

If the SF is 32, each logical operator 231 or 233 carries out a logicaloperation of B₄·I₀⊕B₃·I₁⊕B₂·I₂⊕B₁·I₃⊕B₀·I₄.

If the SF is 16, each logical operator 231 or 233 carries out a logicaloperation of B₃·I₀⊕B₂·I₁⊕B₁·I₂⊕B₀·I₃.

If the SF is 8, each logical operator 231 or 233 carries out a logicaloperation of B₂·I₀⊕B₁·I₁⊕B₀·I₂.

If the SF is 4, each logical operator 231 or 233 carries out a logicaloperation of B₁·I₀⊕B₀·I₁.

The one or more multiplexers 232 selectively output the one or morespreading codes from the one or more logical operators 231 in responseto one or more select signals as the SF related to the one or more dataparts.

The multiplexer 234 selectively outputs the spreading code from thelogical operator 233 in response to a select signal as the SF related tothe control part.

Referring to FIG. 5, there is shown an exemplary diagram illustrating acase where a mobile station uses two channels.

As shown, when the mobile station uses the two channels and SF=2^(N)where N=2 to 8, the spreading code generator 121 generates a spreadingcode of C_(SF, SF/4) to be allocated to the DPDCH or the PCPCH as a datachannel. Further, the spreading code generator 121 generates a spreadingcode of C_(256, 0) to be allocated to the DPCCH or the control channel.Then, the spreader 130 spreads the DPDCH or the PCPCH by the spreadingcode of C_(SF, SF/4). Further, The spreader 130 spreads the controlchannel by the spreading code of C_(256, 0). At this time, thescrambling code generator 123 generates a complex-valued scrambling codeassigned to the mobile station. Further, the complex-valued scramblingcode can be temporarily reserved in the mobile station.

Referring to FIG. 6, there is shown an exemplary diagram depicting acase where multiple mobile stations share a common complex-valuedscrambling code in the PRACH application.

As shown, where the multiple mobile stations share a commoncomplex-valued scrambling code and SF=2^(N) where N=5 to 8 and S=1 to16, the spreading code generator 121 generates a spreading code ofC_(SF, SF(S−1)/16) to be allocated to the PRACH. Further, the spreadingcode generator 121 generates a spreading code of C_(256, 16(S-1)+15) tobe allocated to the control channel.

Then, the spreader 130 spreads the PRACH by the spreading code ofC_(SF, SF(S-1)/16). Also, the spreader 130 spreads the control channelby the spreading code of C_(256, 16(S-1)+15). At this time, thescrambling code generator 123 generates a common complex-valuedscrambling code.

Referring to FIG. 7, there is shown an exemplary diagram showing a casewhere a mobile station uses multiple channels. As shown, where themobile station uses one control channel and two data channels and the SFrelated to the two data channels is 4, the spreading code generator 121generates a spreading code of C_(256, 0) to be allocated to the DPCCH.Further, the spreading code generator 121 generates a spreading code ofC_(4, 1) allocated to the DPDCH 1. Furthermore, the spreading codegenerator 121 generates a spreading code of C_(4, 1) allocated to theDPDCH 2.

Then, the spreader 130 spreads the DPDCH 1 by the spreading code ofC_(4, 1). Further, the spreader 130 spreads the DPDCH 2 by the spreadingcode of C_(4, 1). Furthermore, the spreader 130 spreads the DPCCH by thespreading code of C_(256, 0). At this time, the scrambling codegenerator 123 generates a complex-valued scrambling codes assigned tothe mobile station.

As shown, where the mobile station uses one control channel and threedata channels and the SF related to the three data channels is 4, thespreading code generator 121 further generates a spreading code ofC_(4, 3) to be allocated to the DPDCH 3. Then, the spreader 130 furtherspreads the DPDCH 3 by the spreading code of C_(4, 3).

As shown, where the mobile station uses one control channel and fourdata channels and the SF related to the four data channels is 4, thespreading code generator 121 further generates a spreading code ofC_(4, 3) to be allocated to the DPDCH 4. Then, the spreader 130 furtherspreads the DPDCH 4 by the spreading code of C_(4, 3).

As shown, where the mobile station uses one control channel and fivedata channels and the SF related to the five data channels is 4, thespreading code generator 121 further generates a spreading code ofC_(4, 2) to be allocated to the DPDCH 5. Then, the spreader 130 furtherspreads the DPDCH 5 by the spreading code of C_(4, 2).

As shown, where the two mobile station uses one control channel and sixdata channels and the SF related to the six data channels is 4, thespreading code generator 121 further generates a spreading code ofC_(4, 2) to be allocated to the DPDCH 6. Then, the spreader 130 furtherspreads the DPDCH 6 by the spreading code of C_(4, 2).

Referring to FIG. 8, there is shown a first exemplary view describing adesirable phase difference between rotated points on a phase domainwhere a Walsh rotator rotates points at consecutive chips.

As shown, in case where an SF is 4 and a code number is 0, a spreadingcode of C_(4, 0) is represented by {1, 1, 1, 1}. Further, in case wherethe SF is 4 and a code number is 1, a spreading code of C_(4, 1) isrepresented by {1, 1, −1, −1}.

Assume that two channels are spread by the spreading code ofC_(4, 0)={1, 1, 1, 1} and the spreading code of C_(4, 1)={1, 1, −1, −1},respectively. At this time, real values contained in the spreading codeof C_(4, 0)={1, 1, 1, 1} are represented by points on a real axis of aphase domain. Further, real values contained in the spreading code ofC_(4, 1)={1, 1, −1, −1} are represented by points on an imaginary axisof the phase domain.

At a first or second chip, a point {1, 1}, i.e., a point {circle around(1)} or {circle around (2)}, is designated on the phase domain by firstor second real values contained in the spreading codes of C_(4, 0) andC_(4, 1). At a third or fourth chip, a point {1, −1}, i.e., a point{circle around (3)} or {circle around (4)}, is designated on the phasedomain by third or fourth real values contained in the spreading codesof C_(4, 0) and C_(4, 1). The points {circle around (1)} and {circlearound (2)} are positioned on the same point as each other. Also, thepoints {circle around (3)} and {circle around (4)} are positioned on thesame point as each other. Where the Walsh rotator rotates the points atchips, the points are rotated by a predetermined phase, respectively.

For example, where the Walsh rotator rotates the point {circle around(1)} or {circle around (3)} at an odd chip, the point {circle around(1)} or {circle around (3)} is rotated to a clockwise direction by aphase of 45°. Further, where the Walsh rotator rotates the point {circlearound (2)} or {circle around (4)} at an even chip, the point {circlearound (2)} or {circle around (4)} is rotated to a counterclockwisedirection by the phase of 45°. After rotating the points {circle around(1)} and {circle around (2)} or the points {circle around (3)} and{circle around (4)} at the odd and even chips as two consecutive chips,a phase difference between the rotated points {circle around (1)}′ and{circle around (2)}′ or the rotated points {circle around (3)}′ and{circle around (4)}′ becomes 90°. Where the phase difference between therotated points {circle around (1)}′ and {circle around (2)}′ or therotated points {circle around (3)}′ and {circle around (4)}′ becomes90°, a peak-to-average power ratio (PAPR) of a mobile station can bereduced.

For another example, where the Walsh rotator rotates the point {circlearound (1)} or {circle around (3)} at an odd chip, the point {circlearound (1)} or {circle around (3)} is rotated to the counterclockwisedirection by the phase of 45°. Further, where the Walsh rotator rotatesthe point {circle around (2)} or {circle around (4)} at an even chip,the point {circle around (2)} or {circle around (4)} is rotated to theclockwise direction by the phase of 45°. After rotating the points{circle around (1)} and {circle around (2)} or the points {circle around(3)} and {circle around (4)} at the odd and even chips as twoconsecutive chips, a phase difference between the rotated points {circlearound (1)}″ and {circle around (2)}″ or the rotated points {circlearound (3)}″ and {circle around (4)}″ becomes 90°. Where the phasedifference between the rotated points {circle around (1)}″ and {circlearound (2)}″ or the rotated points {circle around (3)}″ and {circlearound (4)}″ becomes 90°, the peak-to-average power ratio of the mobilestation can be reduced.

Referring to FIG. 9, there is shown a second exemplary view showing adesirable phase difference between rotated points on a phase domainwhere a Walsh rotator rotates points at consecutive chips.

First, assume that two channels are spread by a spreading code ofC_(4, 2)={1, −1, 1, −1} and a spreading code of C_(4, 3)={1, −1, −1, 1},respectively.

At a first chip, a point {1, 1}, i.e., a point {circle around (1)}, isdesignated on the phase domain by first real values contained in thespreading codes of C_(4, 2) and C_(4, 3). At a second chip, a point {−1,−1}, i.e., a point {circle around (2)}, is designated on the phasedomain by second real values contained in the spreading codes ofC_(4, 2) and C_(4, 3). The points {circle around (1)} and {circle around(2)} are symmetrical with respect to a zero point as a center point onthe phase domain.

At a third chip, a point {1, −1}, i.e., a point {circle around (3)}, isdesignated on the phase domain by third real values contained in thespreading codes of C_(4, 2) and C_(4, 3). At a fourth chip, a point {−1,1}, i.e., a point {circle around (4)}, is designated on the phase domainby fourth real values contained in the spreading codes of C_(4, 2) andC_(4, 3). The points {circle around (3)} and {circle around (4)} aresymmetrical with respect to the zero point on the phase domain. Wherethe Walsh rotator rotates the points at chips, the points are rotated bya predetermined phase, respectively.

For example, where the Walsh rotator rotates the point {circle around(1)} or {circle around (3)} at an odd chip, the point {circle around(1)} or {circle around (3)} is rotated to a clockwise direction by aphase of 45°. Further, where the Walsh rotator rotates the point {circlearound (2)} or {circle around (4)} at an even chip, the point {circlearound (2)} or {circle around (4)} is rotated to a counterclockwisedirection by the phase of 45°. After rotating the points {circle around(1)} and {circle around (2)} or the points {circle around (3)} and{circle around (4)} at the odd and even chips as two consecutive chips,a phase difference between the rotated points {circle around (1)}′ and{circle around (2)}′ or the rotated points {circle around (3)}′ and{circle around (4)}′ becomes 90°. Where the phase difference between therotated points {circle around (1)}′ and {circle around (2)}′ or therotated points {circle around (3)}′ and {circle around (4)}′ becomes90°, a peak-to-average power ratio of a mobile station can be reduced.

For another example, where the Walsh rotator rotates the point {circlearound (1)} or {circle around (3)} at an odd chip, the point {circlearound (1)} or {circle around (3)} is rotated to the counterclockwisedirection by the phase of 45°. Further, where the Walsh rotator rotatesthe point {circle around (2)} or {circle around (4)} at an even chip,the point {circle around (2)} or {circle around (4)} is rotated to theclockwise direction by the phase of 45°. After rotating the points{circle around (1)} and {circle around (2)} or the points {circle around(3)} and {circle around (4)} at the odd and even chips as twoconsecutive chips, a phase difference between the rotated points {circlearound (1)}″ and {circle around (2)}″ or the rotated points {circlearound (3)}″ and {circle around (4)}″ becomes 90°. Where the phasedifference between the rotated points {circle around (1)}″ and {circlearound (2)}″ or the rotated points {circle around (3)}″ and {circlearound (4)}″ becomes 90°, the peak-to-average power ratio of the mobilestation can be reduced.

Referring to FIG. 10, there is shown a first exemplary view depicting anundesirable phase difference between rotated points on a phase domainwhere a Walsh rotator rotates points at consecutive chips.

First, assume that two channels are spread by the spreading code ofC_(4, 0)={1, 1, 1, 1} and the spreading code of C_(4, 2)={1, −1, 1, −1},respectively.

At a first chip, a point {1, 1}, i.e., a point {circle around (1)}, isdesignated on the phase domain by first real values contained in thespreading codes of C_(4, 0) and C_(4, 2). At a second chip, a point {1,−1}, i.e., a point {circle around (2)}, is designated on the phasedomain by second real values contained in the spreading codes ofC_(4, 0) and C_(4, 2). The points {circle around (1)} and {circle around(2)} are symmetrical with respect to the real axis on the phase domain.

At a third chip, a point {1, 1}, i.e., a point {circle around (3)}, isdesignated on the phase domain by third real values contained in thespreading codes of C_(4, 0) and C_(4, 2). At a fourth chip, a point {1,−1}, i.e., a point {circle around (4)}, is designated on the phasedomain by fourth real values contained in the spreading codes ofC_(4, 0) and C_(4, 2). The points {circle around (3)} and {circle around(4)} are symmetrical with respect to the real axis on the phase domain.Where the Walsh rotator rotates the points at chips, the points arerotated by a predetermined phase, respectively.

For example, where the Walsh rotator rotates the point {circle around(1)} or {circle around (3)} at an odd chip, the point {circle around(1)} or {circle around (3)} is rotated to a counterclockwise directionby a phase of 45°. Further, where the Walsh rotator rotates the point{circle around (2)} or {circle around (4)} at an even chip, the point{circle around (2)} or {circle around (4)} is rotated to a clockwisedirection by the phase of 45°. After rotating the points {circle around(1)} and {circle around (2)} or the points {circle around (3)} and{circle around (4)} at the odd and even chips as two consecutive chips,a phase difference between the rotated points {circle around (1)}′ and{circle around (2)}′ or the rotated points {circle around (3)}′ and{circle around (4)}′ becomes zero. Where the phase difference betweenthe rotated points {circle around (1)}′ and {circle around (2)}′ or therotated points {circle around (3)}′ and {circle around (4)}′ does notbecome 90°, a peak-to-average power ratio of a mobile station can not bereduced.

Referring to FIGS. 11 and 12, there are shown third exemplary viewsillustrating a desirable phase difference between rotated points on aphase domain where a Walsh rotator rotates points at consecutive chips.

First, assume that data of 1 allocated to a first channel is spread by aspreading code of C_(4, 1)={1, 1, −1, −1}. Further, assume that data of−1 allocated to a second channel is spread by a spreading code ofC_(4, 1)={1, 1, −1, −1}. Furthermore, assume that data of 1 allocated toa third channel is spread by a spreading code of C_(4, 0)={1, 1, 1, 1}.

In terms of the first channel, the spreader 130 shown in FIG. 3multiplies the data of 1 by the spreading code of C_(4, 1)={1, 1, −1,−1}, thereby generating a code of {1, 1, −1, −1}. Further, in terms ofthe second channel, the spreader 130 multiplies the data of −1 by thespreading code of C_(4, 1)={1, 1, −1, −1}, thereby generating a code of{−1, −1, 1, 1}. Furthermore, in terms of the third channel, the spreader130 multiplies the data of 1 by the spreading code of C_(4, 0)={1, 1, 1,1}, thereby generating a code of {1, 1, 1, 1}.

Where the spreader 130 includes an adder 131 shown in FIG. 12, the adder131 generates a code of {0, 0, 2, 2} by adding the code of {−1, −1, 1,1} to the code of {1, 1, 1, 1}. TABLE 1 Chip 1 2 3 4 First Channel 1 1−1 −1 Second Channel −1 −1 1 1 Third Channel 1 1 1 1 Second channel + 00 2 2 Third channel

Table 1 represents the spreading codes allocated to three channels and asum of two channels depending upon chips. At a first or second chip, apoint {1, 0}, i,e., a point {circle around (1)} or {circle around (2)},is designated on the phase domain by first or second real valuescontained in the code of {1, 1, −1, −1} and the code of {0, 0, 2, 2}. Ata third or fourth chip, a point {−1, 2}, i.e., a point {circle around(3)} or {circle around (4)}, is designated on the phase domain by thirdor fourth real values contained in the code of {1, 1, −1, −1} and thecode of {0, 0, 2, 2}. The points {circle around (1)} and {circle around(2)} are positioned on the same point as each other. Also, the points{circle around (3)} and {circle around (4)} are positioned on the samepoint as each other. Where the Walsh rotator rotates the points atchips, the points are rotated by a predetermined phase, respectively.

For example, where the Walsh rotator rotates the point {circle around(1)} or {circle around (3)} at an odd chip, the point {circle around(1)} or {circle around (3)} is rotated to a clockwise direction by aphase of 45°. Further, where the Walsh rotator rotates the point {circlearound (2)} or {circle around (4)} at an even chip, the point {circlearound (2)} or {circle around (4)} is rotated to a counterclockwisedirection by the phase of 45°. After rotating the points {circle around(1)} and {circle around (2)} or the points {circle around (3)} and{circle around (4)} at the odd and even chips as two consecutive chips,a phase difference between the rotated points {circle around (1)}′ and{circle around (2)}′ or the rotated points {circle around (3)}′ and{circle around (4)}′ becomes 90°. Where the phase difference between therotated points {circle around (1)}′ and {circle around (2)}′ or therotated points {circle around (3)}′ and {circle around (4)}′ becomes90°, a peak-to-average power ratio of a mobile station can be reduced.

Referring to FIGS. 13 and 14, there are shown second exemplary viewsillustrating an undesirable phase difference between rotated points on aphase domain where a Walsh rotator rotates points at consecutive chips.

First, assume that data of 1 allocated to a first channel is spread by aspreading code of C_(4, 1)={1, 1, −1, −1}. Further, assume that data of−1 allocated to a second channel is spread by a spreading code ofC_(4, 2)={1, −1, 1, −1}. Furthermore, assume that data of 1 allocated toa third channel is spread by a spreading code of C_(4, 0)={1, 1, 1, 1}.

In terms of the first channel, the spreader 130 shown in FIG. 2multiplies the data of 1 with the spreading code of C_(4, 1)={1, 1, −1,−1}, thereby generating a code of {1, 1, −1, −1}. Further, in terms ofthe second channel, the spreader 130 multiplies the data of −1 by thespreading code of C_(4,) ₂={1, −1, 1, −1}, thereby generating a code of{−1, 1, −1, 1}. Furthermore, in terms of the third channel, the spreader130 multiplies the data of 1 by the spreading code of C_(4, 0)={1, 1, 1,1}, thereby generating a code of {1, 1, 1, 1}.

Where the spreader 130 includes an adder 133 shown in FIG. 14, the adder133 generates a code of {0, 2, 0, 2} by adding the code of {−1, 1, −1,1} to the code of {1, 1, 1, 1}.

Table 2 Chip 1 2 3 4 First Channel 1 1 −1 −1 Second Channel −1 1 −1 1Third Channel 1 1 1 1 Second channel + 0 2 0 2 third channel

Table 2 represents the spreading codes allocated to three channels and asum of two channels depending upon chips. At a first chip, a point {1,0}, i.e., a point {circle around (1)}, is designated on the phase domainby first real values contained in the code of {1, 1, −1, −1} and thecode of {0, 2, 0, 2}. At a second chip, a point {1, 2}, i.e., a point{circle around (2)}, is designated on the phase domain by second realvalues contained in the code of {1, 1, −1, −1} and the code of {0, 2, 0,2}. At a third chip, a point {−1, 0}, i.e., a point {circle around (3)},is designated on the phase domain by third real values contained in thecode of {1, 1, −1, −1} and the code of {0, 2, 0, 2}. At a fourth chip, apoint {−1, 2}, i.e., a point {circle around (4)}, is designated on thephase domain by third real values contained in the code of {1, 1, −1,−1} and the code of {0, 2, 0, 2}.

The points {circle around (1)} and {circle around (2)} or the points{circle around (3)} and {circle around (4)} are positioned on differentpoints from each other. Where the Walsh rotator rotates the points atchips, the points are rotated by a predetermined phase, respectively.

For example, where the Walsh rotator rotates the point {circle around(1)} or {circle around (3)} at an odd chip, the point {circle around(1)} or {circle around (3)} is rotated to a clockwise direction by aphase of 45°. Further, where the Walsh rotator rotates the point {circlearound (2)} or {circle around (4)} at an even chip, the point {circlearound (2)} or {circle around (4)} is rotated to a counterclockwisedirection by the phase of 45°. After rotating the points {circle around(3)} and {circle around (4)} at the odd and even chips as twoconsecutive chips, a phase difference between the rotated points {circlearound (3)}′ and {circle around (4)}′ does not become 90°. Where thephase difference between the rotated points {circle around (3)}′ and{circle around (4)}′ does not become 90°, a peak-to-average power ratioof a mobile station can increase.

Further, after rotating the points {circle around (1)} and {circlearound (2)} at the odd and even chips as two consecutive chips, a phasedifference between the rotated points {circle around (1)}′ and {circlearound (2)}′ does not become 90°. Where the phase difference between therotated points {circle around (1)}′ and {circle around (2)}′ does notbecome 90°, the peak-to-average power ratio of a mobile station canincrease.

Referring to FIG. 15, there is shown an exemplary graphical diagramdescribing the probability of peak to average power.

When a mobile station employs two channels and spreading codes ofC_(4, 0)={1, 1, 1, 1} and C_(4, 1)={1, 1, −1, −1} allocated to the twochannels, a curve G1 is shown in the graphical diagram. At this time,the probability of the peak power exceeding the average power by 2.5 dBis approximately 1%.

Further, when a mobile station employs two channels and spreading codesof C_(4, 0)={1, 1, 1, 1} and C_(4, 2)={1, −1, 1, −1} allocated to thetwo channels, a curve G2 is shown in the graphical diagram. At thistime, the probability of the peak power exceeding the average power by2.5 dB is approximately 7%.

Referring to FIG. 16, there is shown a flowchart depicting a method formodulating a data message in a mobile station in accordance with thepresent invention.

As shown, at step S1302, an encoder receives a data message to betransmitted to a base station.

At step S1304, the encoder encodes the data message having one or moredata parts and generates a control part.

At step S1306, the encoder evaluates an SF related to the one or moredata parts to send the SF from an encoder to a CPU.

At step S1308, the CPU produces information necessary to generatespreading codes to be allocated to channels.

At step S1310, a code generator generates the spreading codes.

At step S1312, a spreader spreads the control part and the one or moredata parts by the spreading codes.

At step S1314, a scrambler scrambles the control part and the one ormore data parts spread and a complex-valued scrambling code, to therebygenerate a channel-modulated signal having a plurality of pairs ofin-phase (I) and quadrature-phase (Q) data in the mobile station.

Referring to FIGS. 17 to 19, there are flowcharts illustrative of aprocedure for producing information necessary to generate spreadingcodes to be allocated to channels.

As shown, at step S1402, the CPU receives the SF related to the one ormore data parts from the encoder.

At step S1404, the CPU determines a type of an event.

At step S1408, if the event is a case where a mobile station uses twochannels, the CPU produces an SF of 256 and a code number of 0 relatedto the control part.

At step S1410, the CPU produces a code number of SF/4 related to the onedata part where SF=2^(N) and N=2 to 8.

At step S1412, the CPU sends the code numbers and the SFs related to thedata and control parts to the code generator.

On the other hand, at step S1414, if the event is a case where multiplemobile stations share a common complex-valued scrambling code, the CPUproduces a signature S.

At step S1416, the CPU produces the SF of 256 and a code number of16(S−1)+15 related to the control part where S=1 to 16.

At step S1418, the CPU produces a code number of SF(S−1)/16 related tothe one data part where SF=2^(N), N=2 to 8 and S=1 to 16.

At step S1420, the CPU sends the code numbers and the SFs related to thedata and control parts to the code generator.

On the other hand, at step S1424, if the event is a case where a mobilestation uses multiple channels, the CPU produces a code number of 0 andthe SF of 256 related to the control part allocated to the controlchannel.

At step S1502, the CPU determines the number of data channels.

At step S1504, if the number of data channels is two data channels, theCPU produces a code number of 1 and an SF of 4 related to a first datapart allocated to a first data channel coupled to an I branch.

At step S1506, the CPU produces a code number of 1 and the SF of 4related to a second data part allocated to a second data channel.

On the other hand, at step S1508, if the number of data channels isthree data channels, the CPU produces the code number of 1 and the SF of4 related to the first data part allocated to the first data channel.

At step S1510, the CPU produces the code number of 1 and the SF of 4related to the second data part allocated to the second data channel.

At step S1512, the CPU produces a code number of 3 and the SF of 4related to the third data part allocated to the third data channel.

On the other hand, at step S1514, if the number of data channels is fourdata channels, the CPU produces the code number of 1 and the SF of 4related to the first data part allocated to the first data channel.

At step S1516, the CPU produces the code number of 1 and the SF of 4related to the second data part allocated to the second data channel.

At step S1518, the CPU produces the code number of 3 and the SF of 4related to the third data part allocated to the third data channel.

At step S1520, the CPU produces the code number of 3 and the SF of 4related to a fourth data part allocated to a fourth data channel.

On the other hand, at step S1522, if the number of data channels is fivedata channels, the CPU produces the code number of 1 and the SF of 4related to the first data part allocated to the first data channel.

At step S1524, the CPU produces the code number of 1 and the SF of 4related to the second data part allocated to the second data channel.

At step S1526, the CPU produces the code number of 3 and the SF of 4related to the third data part allocated to the third data channel.

At step S1528, the CPU produces the code number of 3 and the SF of 4related to the fourth data part allocated to the fourth data channel.

At step S1530, the CPU produces the code number of 2 and the SF of 4related to a fifth data part allocated to a fifth data channel.

On the other hand, at step S1532, if the number of data channels is sixdata channels, the CPU produces the code number of 1 and the SF of 4related to the first data part allocated to the first data channel.

At step S1534, the CPU produces the code number of 1 and the SF of 4related to the second data part allocated to the second data channel.

At step S1536, the CPU produces the code number of 3 and the SF of 4related to the third data part allocated to the third data channel.

At step S1538, the CPU produces the code number of 3 and the SF of 4related to the fourth data part allocated to the fourth data channel.

At step S1540, the CPU produces the code number of 2 and the SF of 4related to the fifth data part allocated to the fifth data channel.

At step S1542, the CPU produces the code number of 2 and the SF of 4related to a sixth data part allocated to a sixth data channel.

At step S1521, the CPU transmits the code numbers and the SFs related tothe data and control parts to the code generator.

Referring to FIG. 20, there is shown a flowchart showing a procedure ofgenerating the spreading codes.

As shown, at step S1702, registers receive the code numbers and the SFsfrom the CPU.

At step S1704, registers store the code numbers and the SFs.

At step S1706, logical operators carry out logical operations inresponse to an 8-bit count value, thereby generating the spreadingcodes.

At step S1708, multiplexers select the spreading codes in response tothe SFs as select signals.

Referring to FIGS. 21 and 22, there are shown flowcharts describing aprocedure of carrying out the logical operations in response to the8-bit count value, thereby generating the spreading codes.

As shown, at step S1802, each register receives a code number ofI₇I₆I₅I₄I₃I₂I₁I₀ and a predetermined SF.

At step S1804, each register receives an 8-bit count value ofB₇B₆B₅B₄B₃B₂B₁B₀ from an 8-bit counter.

At step S1806, a type of the predetermined SF is determined.

At step S1808, if the predetermined SF is SF₂₅₆, each logical operatorcarries out a logical operation ofB₇·I₀⊕B₆·I₁⊕B₅·I₂⊕B₄·I₃⊕B₃·I₄⊕B₂·I₅⊕B₁·I₆⊕B₀·I₇.

At step S1810, if the predetermined SF is SF₁₂₈, each logical operatorcarries out a logical operation ofB₆·I₀⊕B₅·I₁⊕B₄·I₂⊕B₃·I₃⊕B₂·I₄⊕B₁·I₅⊕B₀·I₆.

At step S1812, if the predetermined SF is SF₆₄, each logical operatorcarries out a logical operation of B₅·I₀⊕B₄·I₁⊕B₃·I₂⊕B₂·I₃⊕B₁·I₄⊕B₀·I₅.

At step S1814, if the predetermined SF is SF₃₂, each logical operatorcarries out a logical operation of B₄·I₀⊕B₃·I₁⊕B₂·I₂⊕B₁·I₃⊕B₀·I₄.

At step S1816, if the predetermined SF is SF₁₆, each logical operatorcarries out a logical operation of B₃·I₀⊕B₂·I₁⊕B₁·I₂⊕B₀·I₃.

At step S1818, if the predetermined SF is SF₈, each logical operatorcarries out a logical operation of B₂·I₀⊕B₁·I₁⊕B₀·I₂.

At step S1820, if the predetermined SF is SF₄, each logical operatorcarries out a logical operation of B₁·I₀⊕B₀·I₁.

At step S1822, each multiplexer generates a spreading code in responseto the SF.

Although the preferred embodiments of the invention have been disclosedfor illustrative purposes, those skilled in the art will appreciate thatvarious modifications, additions and substitutions are possible, withoutdeparting from the scope and spirit of the invention as disclosed in theaccompanying claims.

1-82. (canceled)
 83. A spreading method comprising the steps of:allocating a plurality of data channels for active transmission fromavailable data channels that have a sequential order from CH₁ throughCH_(x) where x represents the highest number of data channels available,with the odd numbered data channels being associated with an in-phasepart of a transmission and the even numbered data channels beingassociated with a quadrature-phase part of the transmission, wherein thedata channels for active transmission are selected from the availabledata channels according to a predetermined procedure so that the activetransmission channels comprise channel one through the channel numbercorresponding to the number of active transmission data channels; andapplying a spreading sequence to each data channel in activetransmission, wherein each spreading sequence comprises a spreadingfactor of four and each spreading sequence is represented by C_(4,k)where the spreading sequence C_(4,k) is applied to data channel CH_(n);where if n=1, 2, then k=1; if n=3, 4, then k=3, and if n=5, 6, then k=2.84. The method of claim 83, wherein the spreading sequence represents anorthogonal variable spreading factor code.
 85. The method of claim 83,wherein C_(4,k) when k=1 is represented by a series of a pair ofpositive one integer and a pair of negative one integer.
 86. The methodof claim 83, wherein C_(4,k) when k=3 is represented by a series of apair comprising a sequence of positive one integer and negative oneinteger and a pair comprising a sequence of negative one integer andpositive one integer.
 87. The method of claim 83, wherein C_(4,k) whenk=2 is represented by a series of a sequence of positive one integer andnegative one integer.
 88. The method of claim 83, further comprising thesteps of: receiving a control channel and applying a control spreadingsequence to the control channel.
 89. An apparatus comprising: aplurality of data channels allocated from available data channels thathave a sequential order from CH₁ through CH_(x) where x represents thehighest number of data channels available, with the odd numbered datachannels being associated with an in-phase part of a transmission andthe even numbered data channels being associated with a quadrature-phasepart of the transmission, wherein the data channels for activetransmission are selected from the available data channels according toa predetermined procedure so that the active transmission channelscomprise channel one through the channel number corresponding to thenumber of active transmission data channels; and a spreader for applyinga spreading sequence to each data channel in active transmission,wherein each spreading sequence comprises a spreading factor of four andeach spreading sequence is represented by C_(4,k) where the spreadingsequence C_(4,k) is applied to data channel CH_(n); where if n=1, 2,then k=1; if n=3, 4, then k=3, and if n=5, 6, then k=2.
 90. The unit ofclaim 89, wherein the spreading sequence represents an orthogonalvariable spreading factor code.
 91. The unit of claim 89, whereinC_(4,k) when k=1 is represented by a series of a pair of positive oneinteger and a pair of negative one integer.
 92. The unit of claim 89,wherein C_(4,k) when k=3 is represented by a series of a pair comprisinga sequence of positive one integer and negative one integer and a paircomprising a sequence of negative one integer and positive one integer.93. The unit of claim 89, wherein C_(4,k) when k=2 is represented by aseries of a sequence of positive one integer and negative one integer.94. The unit of claim 89, wherein the spreading unit further comprises acontrol channel wherein a control spreading sequence is applied to thecontrol channel.
 95. An apparatus comprising: allocating means forallocating a plurality of data channels for active transmission fromavailable data channels that have a sequential order from CH₁ throughCH_(x) where x represents the highest number of data channels available,with the odd numbered data channels being associated with an in-phasepart of a transmission and the even numbered data channels beingassociated with a quadrature-phase part of the transmission, wherein thedata channels for active transmission are selected from the availabledata channels according to a predetermined procedure so that the activetransmission channels comprise channel one through the channel numbercorresponding to the number of active transmission data channels; andspreading means for applying a spreading sequence to each data channelin active transmission, wherein each spreading sequence comprises aspreading factor of four and each spreading sequence is represented byC_(4,k) where the spreading sequence C_(4,k) is applied to data channelCH_(n); where if n=1, 2, then k=1; if n=3, 4, then k=3, and if n=5, 6,then k=2.
 96. The unit of claim 95, wherein the spreading sequencerepresents an orthogonal variable spreading factor code.
 97. The unit ofclaim 95, wherein C_(4,k) when k=1 is represented by a series of a pairof positive one integer and a pair of negative one integer.
 98. The unitof claim 95, wherein C_(4,k) when k=3 is represented by a series of apair comprising a sequence of positive one integer and negative oneinteger and a pair comprising a sequence of negative one integer andpositive one integer.
 99. The unit of claim 95, wherein C_(4,k) when k=2is represented by a series of a sequence of positive one integer andnegative one integer.
 100. The unit of claim 95, wherein the spreadingunit further comprises a control channel wherein a control spreadingsequence is applied to the control channel.
 101. A recording mediumcontaining computer-executable instructions to perform a spreadingmethod, the method comprising: allocating a plurality of data channelsfor active transmission from available data channels that have asequential order from CH₁ through CH_(x) where x represents the highestnumber of data channels available, with the odd numbered data channelsbeing associated with an in-phase part of a transmission and the evennumbered data channels being associated with a quadrature-phase part ofthe transmission, wherein the data channels for active transmission areselected from the available data channels according to a predeterminedprocedure so that the active transmission channels comprise channel onethrough the channel number corresponding to the number of activetransmission data channels; and applying a spreading sequence to eachdata channel in active transmission, wherein each spreading sequencecomprises a spreading factor of four and each spreading sequence isrepresented by C_(4,k) where the spreading sequence C_(4,k) is appliedto data channel CH_(n); where if n=1, 2, then k=1; if n=3, 4, then k=3,and if n=5, 6, then k=2.
 102. The recording medium of claim 101, whereinthe spreading sequence represents an orthogonal variable spreadingfactor code.
 103. The recording medium of claim 101, wherein C_(4,k)when k=1 is represented by a series of a pair of positive one integerand a pair of negative one integer.
 104. The recording medium of claim101, wherein C_(4,k) when k=3 is represented by a series of a paircomprising a sequence of positive one integer and negative one integerand a pair comprising a sequence of negative one integer and positiveone integer.
 105. The recording medium of claim 101, wherein C_(4,k)when k=2 is represented by a series of a sequence of positive oneinteger and negative one integer.
 106. The recording medium of claim101, further comprising: receiving a control channel and applying acontrol spreading sequence to the control channel.
 107. A spreadingmethod comprising the steps of: allocating a plurality of data channelsfor active transmission from available data channels that have asequential order from CH₁ through CH_(x) where x represents the highestnumber of data channels available, with the odd numbered data channelsbeing associated with an in-phase part of a transmission and the evennumbered data channels being associated with a quadrature-phase part ofthe transmission, wherein the data channels for active transmission areselected from the available data channels according to a predeterminedprocedure so that the active transmission channels comprise channel onethrough the channel number corresponding to the number of activetransmission data channels; and applying one of a plurality oforthogonal variable factor sequences to each data channel in activetransmission, wherein the plurality of orthogonal variable factorsequences comprise at least a first orthogonal variable factor sequencecorresponding to C_(SF, 1) and a second orthogonal variable factorsequence corresponding to C_(SF, 3) where SF is a spreading factor offour or greater and wherein the first orthogonal variable factorsequence is applied to channels one and two and the second orthogonalvariable factor sequence is applied to channel three.
 108. The method ofclaim 107, wherein the spreading sequence represents an orthogonalvariable spreading factor code.
 109. The method of claim 107, whereinthe first spreading sequence is represented by a series of a pair ofpositive one integer and a pair of negative one integer.
 110. The methodof claim 107, wherein the third spreading sequence is represented by aseries of a pair comprising a sequence of positive one integer andnegative one integer and a pair comprising a sequence of negative oneinteger and positive one integer.
 111. The method of claim 107, whereinthe second spreading sequence is represented by a series of a sequenceof positive one integer and negative one integer.
 112. The method ofclaim 107, further comprising the steps of: receiving a control channeland applying a control spreading sequence to the control channel. 113.An apparatus comprising: a plurality of data channels allocated fromavailable data channels that have a sequential order from CH₁ throughCH_(x) where x represents the highest number of data channels available,with the odd numbered data channels being associated with an in-phasepart of a transmission and the even numbered data channels beingassociated with a quadrature-phase part of the transmission, wherein thedata channels for active transmission are selected from the availabledata channels according to a predetermined procedure so that the activetransmission channels comprise channel one through the channel numbercorresponding to the number of active transmission data channels; and aspreader that applies one of a plurality of orthogonal variable factorsequences to each data channel in active transmission, wherein theplurality of orthogonal variable factor sequences comprise at least afirst orthogonal variable factor sequence corresponding to C_(SF, 1) anda second orthogonal variable factor sequence corresponding to C_(SF, 3)where SF is a spreading factor of four or greater and wherein the firstorthogonal variable factor sequence is applied to channels one and twoand the second orthogonal variable factor sequence is applied to channelthree.
 114. The spreading unit of claim 113, wherein the spreadingsequence represents an orthogonal variable spreading factor code. 115.The spreading unit of claim 113, wherein the first spreading sequence isrepresented by a series of a pair of positive one integer and a pair ofnegative one integer.
 116. The spreading unit of claim 113, wherein thethird spreading sequence is represented by a series of a pair comprisinga sequence of positive one integer and negative one integer and a paircomprising a sequence of negative one integer and positive one integer.117. The spreading unit of claim 113, wherein the second spreadingsequence is represented by a series of a sequence of positive oneinteger and negative one integer.
 118. The spreading unit of claim 113,wherein the spreading unit further comprises a control channel wherein acontrol spreading sequence is applied to the control channel.
 119. Anapparatus comprising: allocating means for allocating a plurality ofdata channels for active transmission from available data channels thathave a sequential order from CH₁ through CH_(x) where x represents thehighest number of data channels available, with the odd numbered datachannels being associated with an in-phase part of a transmission andthe even numbered data channels being associated with a quadrature-phasepart of the transmission, wherein the data channels for activetransmission are selected from the available data channels according toa predetermined procedure so that the active transmission channelscomprise channel one through the channel number corresponding to thenumber of active transmission data channels; and spreading means forapplying one of a plurality of orthogonal variable factor sequences toeach data channel in active transmission, wherein the plurality oforthogonal variable factor sequences comprise at least a firstorthogonal variable factor sequence corresponding to C_(SF, 1) and asecond orthogonal variable factor sequence corresponding to C_(SF, 3)where SF is a spreading factor of four or greater and wherein the firstorthogonal variable factor sequence is applied to channels one and twoand the second orthogonal variable factor sequence is applied to channelthree.
 120. The spreading unit of claim 119, wherein the spreadingsequence represents an orthogonal variable spreading factor code. 121.The spreading unit of claim 119, wherein the first spreading sequence isrepresented by a series of a pair of positive one integer and a pair ofnegative one integer.
 122. The spreading unit of claim 119, wherein thethird spreading sequence is represented by a series of a pair comprisinga sequence of positive one integer and negative one integer and a paircomprising a sequence of negative one integer and positive one integer.123. The spreading unit of claim 119, wherein the second spreadingsequence is represented by a series of a sequence of positive oneinteger and negative one integer.
 124. The spreading unit of claim 119,wherein the spreading unit further comprises a control channel wherein acontrol spreading sequence is applied to the control channel.
 125. Arecording medium containing computer-executable instructions to performa spreading method, the method comprising: allocating a plurality ofdata channels for active transmission from available data channels thathave a sequential order from CH₁ through CH_(x) where x represents thehighest number of data channels available, with the odd numbered datachannels being associated with an in-phase part of a transmission andthe even numbered data channels being associated with a quadrature-phasepart of the transmission, wherein the data channels for activetransmission are selected from the available data channels according toa predetermined procedure so that the active transmission channelscomprise channel one through the channel number corresponding to thenumber of active transmission data channels; and applying one of aplurality of orthogonal variable factor sequences to each data channelin active transmission, wherein the plurality of orthogonal variablefactor sequences comprise at least a first orthogonal variable factorsequence corresponding to C_(SF, 1) and a second orthogonal variablefactor sequence corresponding to C_(SF, 3) where SF is a spreadingfactor of four or greater and wherein the first orthogonal variablefactor sequence is applied to channels one and two and the secondorthogonal variable factor sequence is applied to channel three. 126.The recording medium of claim 125, wherein the spreading sequencerepresents an orthogonal variable spreading factor code.
 127. Therecording medium of claim 125, wherein the first spreading sequence isrepresented by a series of a pair of positive one integer and a pair ofnegative one integer.
 128. The recording medium of claim 125, whereinthe third spreading sequence is represented by a series of a paircomprising a sequence of positive one integer and negative one integerand a pair comprising a sequence of negative one integer and positiveone integer.
 129. The recording medium of claim 125, wherein the secondspreading sequence is represented by a series of a sequence of positiveone integer and negative one integer.
 130. The recording medium of claim125, further comprising: receiving a control channel and applying acontrol spreading sequence to the control channel.